International Journal of ChemTech Research CODEN (USA): IJCRGG, ISSN: 0974-4290, ISSN(Online):2455-9555 Vol.10 No.2, pp 393-398, 2017 Economic importance of date palm pests in Aljouf region, Kingdom of Saudi Arabia El- Kholy, M.Y.1,2* and Abdel-Moniem, A.S.H.2,3 1Department of Biology, College of Science, Aljouf University, Sakaka, Aljouf, Kingdom of Saudi Arabia. 2Department of Pests and Plant Protection, National Research Centre, Dokki, Cairo, Egypt. 3Department of Plant Protection, Faculty of Agricultural, Beni Suef University, Egypt Abstract: The Insect pests attacking date palm trees at Aljouf region,Kingdom of Saudi Arabia, were surveyed throughout two successive years in Sakaka. Survey covered existing insect species, stage(s) causing damage, frequency of occurrence, period of occurrence and attacked plant parts).Eleven insect pests belonging to nine families from the orders Homoptera, Coleoptera, Lepidoptera and Hymenoptera were recorded. The most dominant and economically important pests were four scale insects (Asterolecanium phoenicis Rao., Parlatoria blanchardi, Phoenicococcus marlatti and Fiorinia phoenicis Bal.,) and Batrachedra amydraula, Ommatissus binotatus lybicusBergevin, Oryctes spp. and Phonopate frontalis Fahraeus. Fermented or decayed damaged plant parts hosted Drosophila larvae and/or adults. Key word: Phoenix dactylifera, Date palm tree, Insect Pests, Economic importance. Introduction Date palm tree Phoenix dactylifera L. is mentioned in the holy Quran. It has a special consideration in our hearts as Muslims and Arabs. This tree is an important component of Arab World Flora. Date palm tree is considered one of the fruit trees that belong to Arecaceae. Date palm is one of the oldest known fruit crops and has been cultivated in North Africa and the Middle East for at least 5000 years (Zohary and Hopf, 1). The exact center of origin of date palm is unknown, but it is most likely originated from ancient Mesopotamia (Southern Iraq) or western India (Wrigley, 2). From the center of origin, date palm cultivation spread throughout the Arabian Peninsula, North Africa, and the Middle East. Date palm culture had apparently spread into Egypt by the middle of the second millennium BCE, the spread of date palm cultivation later accompanied the expansion of Islam and reached Southern Spain and Pakistan. The Spanish were the first to introduce date palms outside the Arabian Peninsula, North Africa, the Middle East, South Asia, carrying them to America (Nixon, 3). During the past three centuries, date palms were introduced to new production areas in Australia, India/Pakistan, Mexico, southern Africa, South America, and the United States (Chao and Krueger, 4). Arab countries possess 70% of world's date palms and responsible for 67% of the global date production (Juhany, 5). The 10 top date producing countries in the world are Egypt, Saudi Arabia, Iran, United Arab Emirates, Pakistan, Algeria, Sudan, Oman, Libya and Tunisia (Kader and Hussein, 6). Date palms are attacked by many pests and diseases and their nature and severity vary with cultivar, location, weather and cultural practices (Zaid et al.,7). Factors that negatively affect date palm production, El- Kholy, M.Y. and Abdel-Moniem A./International Journal of ChemTech Research, 2017,10(2): 393-398. 394 particularly in traditional date cultivation include crowding of trees, retention of old or unproductive trees, planting of mixed cultivars or seedlings, salt accumulation, poor drainage, insufficient irrigation, fertilization or tillage, lack of insect pests and diseases control, competition with other crops and weeds, soil degradation and water scarcity (Carpenter, 8). The most comprehensive publication available on pests and diseases of date palm was given by Carpenter and Elmer (Carpenter and Elmer, 9) who reported 54 species of mite and insect pests of date palm worldwide. Iraq (Al-Jboory, 10), Kuwait, Bahrain and United Arab Emirates and Yemen (El-Haidari, 11), Saudi Arabia (Hammad and Kadous, 12). The objective of this work is to make an updated, list of date palm mite and insect pests worldwide that can serve as baseline for more comprehensive data base. In this work, the date palm arthropods are classified into pests and are listed, according to their preferred part on the tree and economic importance. Materials And Methods Survey of the insect pests attacking date palm trees in Aljouf region, Kingdom of Saudi Arabia, was carried out at Sakaka city, from September2015 until October 2016. Several palm growing locations, scattered all over the region, were inspected for insect infestations once every month. At any selected location, five random trees-together with their offshoots-were carefully examined. Inspection covered all plant parts (e.g. roots, stem, leaflets, leaf mid-rib, spathes, female flowers and fruits). Any existing insect stage(s) or infestation symptoms were identified on-site as far as possible. In case of uncertainty, samples of the occurring stage(s) were transferred in suitable containers to the laboratory for proper identification. Laboratory identification of the specimens was made either under the stereoscopic binocular or after mounting on microscopic slides. Whenever further identification assistance was required, the specimens were referred to the appropriate taxonomist(s) at the Entomological Collection Division, Department of Pests and Plant Protection, National Research Centre, Dokki, Cairo, Egypt. Monthly examination of the trees further included an arbitrary evaluation of the frequency of occurrence of the surveyed insects (as rare, frequent or common).The period of occurrence of every surveyed insect pest was also approximately determined. Results A list of the insects recorded on date palm trees in Sakaka , Kingdom of Saudi Arabia, is given in (Table 1). The obtained results show that, date palm trees were subject to infestation with 11insect pests belonging to 9 families from the orders Homoptera (3 species), Coleoptera (3 species), Lepidoptera (2 species) and Hymenoptera (1species). Larvae and adult flies of Drosophila melanogaster Meigen. (Drosophilidae: Diptera) were also seen during autumn (September-November) on the fermented fruits primarily attacked with other pests. Table (1): Insect pests associated with date palm cultivated at Sakaka in Aljouf region, 2015 and 2016. Attacked No. Common name Scientific name Family Order Occurrence plant parts Ommatissus Date palm 1. binotatus Tropiduchidae Homoptera Lt, Ft & Mr Apr.- May Dubas bug lybicusBergevin Asterolecanium 2. Green Soft Scale Asterolecaniidae Homoptera Lt & Mr Sep. - Dec. phoenicis Rao. Date palm White Parlatoria Lb, Lt, Ff & 3. Diaspididae Homoptera Mar. - Dec. scale blanchardi Targ. Ft Date palm Red Phoenicoccus Lb, Lt, Ff 4. Diaspididae Homoptera Mar.- Dec. scale marlatti Cockerell. &Ft Date Palm Fiorinia phoenicis 5. Brown Flat Diaspididae Homoptera Lt & Mr Mar.- Dec. Bal. Scale Phonopate frontalis 6. Frond Borer Bostrychidae Coleoptera Ff &Mr Jan.- Dec. Fahraeus 7. Fruit Stalk Borer Oryctes spp. Scarabaeidae Coleoptera Mr & Ft Apr.- May El- Kholy, M.Y. and Abdel-Moniem A./International Journal of ChemTech Research, 2017,10(2): 393-398. 395 Tribolium 8. Red flour beetle Tenebrionidae Coloeptera Ft Dec.- Jan. castaneum(Herbst) Batrachedra 9. Lesser date moth Cosmopterygidae Lepidoptera Ff &Ft Apr.- Aug. amydraulaMeyrick 10. Ephestia moth Ephestia spp Pyralidae Lepidoptera Ft Sep.- Dec. 11. Oriental wasp Vespa orientalisFab. Vespidae Hymenoptera Ft Sep.- Oct. Lb: leaf base. Lt: leaflet. Ff: female flower. Ft: fruit. Mr: mid- rib Fig. 1 Fig. 2 Fig.3 Fig. 6 Fig.4 Fig. 5 Fig. 8 Fig. 7 Fig. 9 Fig. 10 Fig. 11 Ommatissus binotatus lybicus Bergevin (Homoptera: Tropiduchidae). Adult and nymph are the Infesting stages; it was observed that it suck the sap from the leaflets, midrib of the frond and the fruit stalk (Fig.1). The part attacked exuded sap from the punctures made by the insect mouthparts. The insects excreted honeydew (Fig. 2). Few adults and nymphs were found during the survey between 2015 and 2016, particularly in Apr. and May. Asterolecanium phoenicis Rao (Homoptera: Asterolecanidae). Adult is the Infesting stage, it was observed that it suck the sap from the leaflet, midrib and bunches (Fig. 3); infested places became discolored, turning yellowish green. This scale was found mainly on the midrib of the leaves and on upper side of the leaves. It was noticed in all visited fields in Sakaka2015 and 2016 but with inconsiderable damage. El- Kholy, M.Y. and Abdel-Moniem A./International Journal of ChemTech Research, 2017,10(2): 393-398. 396 Parlatoria blanchardi Targ. (Homoptera: Diaspididae). Adult is the Infesting stage, it was observed that it suck the sap from the leaflet, midrib and the dates, under the scale, a discolored area was observed on leaflet, turned yellowish then darker as a sign of dryness. Heavy infestation caused the frond to prematurely drying. This scale was found mainly on the leaflet specially the basal part. It was noticed in all fields in Sakaka2015 and 2016. Phoenicococcus marlatti Cockerell (Homoptera: Diaspididae). Adult is the infesting stage, it was observed that it suck the sap from the green frond bases leaving grey to brown spots. It was mainly found at the fronds that cover with the fiber material of the tree. It was found in all visited places in Sakaka between 2015 to 2016. It could be considered a secondary pest. Fiorinia phoenicis Bal.(Homoptera: Diaspididae). Adult is in the Infesting stage, it was observed that it suck the sap from the green frond bases leaving brown spots(Fig. 4). It was found in all visited places in Sakaka between 2015 to 2016. Phonopate frontalis Fahraeus(Coleoptera: Bostrychidae). Adult is the Infesting stage,It was observed that the adult made a surface mine in the midrib. It was found in all visited places in Sakaka between 2015 to 2016 (Fig. 5). Oryctes spp. (L.) (Coleoptera: Scarabidae). BeetleInfesting stage is adult and larvae. It was observed that the adult made a surface mine in the midrib of fruit stalk; the mine was dark in colour (Fig. 6). The dates in the unattacked side did not die but became smaller in size.